The description relates to an integrated circuit having a resistance temperature sensor, and for semiconductor components.
Power transistors such as DMOS transistors (double diffused metal oxide semiconductor transistors) find multiple application in semiconductor applications. During operation of the power transistors, a wide variety of switching states occur, in which in part very large power losses are converted into heat. Such switching states associated with large power losses are critical since the temperature rises greatly in this case and the power transistors can be destroyed by overheating. In order to protect the transistors against damage in such critical switching states, temperature sensors are often used. Ideally, the temperature sensors are positioned as close as possible to or in the cell array of the power transistor in order that a temperature rise on account of energy loss converted into heat is detected early and rapidly and that the power transistor is turned off in good time before self-destruction on account of overheating byFranz an auxiliary circuit such as a logic circuit. In this case, a resistance situated in the cell array of the power transistor can be used as a rapidly reacting temperature sensor. The temperature sensor changes its absolute resistance value with temperature in the characteristic manner, in which case it is possible to derive a turn-off signal for turning off the power transistor when a defined maximum permissible resistance value is reached. However, this concept with a resistance temperature sensor often fails in practice because of excessively large manufacturing variations with which a resistance temperature sensor of this type can be produced, since the absolute value of the resistance can be used as a turn-off threshold only with difficulty.
In the case of resistance temperature sensors which are integrated into a cell array having trenches and mesa regions lying between the trenches as poly resistance within the trenches or as resistance in the mesa regions, the problem occurs that with the fluctuating width of the trenches or the mesa regions, the resistances fluctuate very greatly with regard to their absolute resistance value. Fluctuations of +/−50% with regard to an average resistance value can occur in this case. However, such large fluctuations prevent a practical use of resistances of this type as a temperature sensor.
For these and other reasons, there is a need for the present invention.